Maria Blassioli | EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária (original) (raw)

Papers by Maria Blassioli

Pesquisa Agropecuária Brasileira, 2008

The objective of this work was to improve the mass rearing technique of Euschistus heros in labor... more The objective of this work was to improve the mass rearing technique of Euschistus heros in laboratory. Nymphs and adults were reared at densities 100, 200, 300 and 400 eggs per Petri dish (9 cm diameter), and at 50, 100, 150 and 200 couples per rearing cages (900 mL), respectively. Survival rate of immature stages and survivorship and reproduction of adults were determinated. Survivorship of nymph to adult was the highest (89%) at density 100 eggs per dish. Adult survivorship was independent of density, and 100 couples per cage were the best to improve quality of the produced progeny. In these conditions, fecundity was 160.8±9.28 eggs per female, and a total of 8,950±456 eggs per cage per month was produced. Two hundred couples per cage showed a negative effect on reproduction, which decreased to 65%. With this technique, a colony of 35 cages with 100 couples per cage yields about 313.3 thousands eggs per month, which is enough to supply the egg parasitoid Telenomus podisi to colon...

Entomologia Experimentalis et Applicata, 2013

ABSTRACT Parasitoids use herbivore‐induced plant volatiles (HIPVs) to locate their hosts. However... more ABSTRACT Parasitoids use herbivore‐induced plant volatiles (HIPVs) to locate their hosts. However, there are few studies in soybean showing the mechanisms involved in the attraction of natural enemies to their hosts and prey. The objective of this study was to evaluate the influence of volatile organic compounds (VOCs) of soybean, Glycine max (L.) Merr. (Fabaceae) (cv. Dowling), that were induced after injury caused by Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), on the searching behavior of the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Scelionidae). Four HIPVs from soybean, (E,E)‐α‐farnesene, methyl salicylate, (Z)‐3‐hexenyl acetate, and (E)‐2‐octen‐1‐ol, were selected, prepared from standards at various concentrations (10−6 to 10−1 m), and tested individually and in combinations using a two‐choice olfactometer (type Y). Telenomus podisi displayed a preference only for (E,E)‐α‐farnesene at 10−5 m when tested individually and compared to hexane, but they did not respond to the other compounds tested individually at any concentration or when combinations of these compounds were tested. However, the parasitoids stayed longer in the olfactometer arm with the mixture of (E,E)‐α‐farnesene + methyl salicylate at 10−5 m than in the arm containing hexane. The results suggest that (E,E)‐α‐farnesene and methyl salicylate might help T. podisi to determine the presence of stink bugs on a plant. In addition, bioassays were conducted to compare (E,E)‐α‐farnesene vs. the volatiles emitted by undamaged and E. heros‐damaged plants, to evaluate whether (E,E)‐α‐farnesene was the main cue used by T. podisi or whether other minor compounds from the plants and/or the background might also be used to locate its host. The results suggest that minor volatile compounds from soybean plants or from its surroundings are involved in the host‐searching behavior of T. podisi.

Journal of Economic Entomology, 2016

Journal of Economic Entomology thank the following scientists for their voluntary commitment of v... more Journal of Economic Entomology thank the following scientists for their voluntary commitment of valuable professional time and expertise to peer reviewing manuscripts submitted for publication in our journal. The quality and scientific stature of the journal depends on the conscientious efforts of these individuals.

Animal Behaviour, 2011

foraging behaviour parasitoid eavesdropping Scelionidae stink bug Telenomus podisi vibratory comm... more foraging behaviour parasitoid eavesdropping Scelionidae stink bug Telenomus podisi vibratory communication

Pesquisa Agropecuaria Brasileira, 2006

The objective of this work was to study the foraging behavior of Telenomus podisi Ashmead (Hymeno... more The objective of this work was to study the foraging behavior of Telenomus podisi Ashmead (Hymenoptera: Scelionidae) in the presence of stimuli from its host, Euschistus heros (Heteroptera: Pentatomidae). The stimuli selected were: egg mass; virgin males and females; volatile extracts of sexually mature males and females; components of male sex pheromone; a component of the alarm pheromone, hexane and an empty cage as control. In a closed arena, the parasitoids were given the choice between single and combined stimuli presented to them simultaneously. To find the host egg, T. podisi primarily uses the sensory cues released from the male insects. The orientation toward odors of male chemical extract indicates that a source of kairomone was detected. Gas chromatographic analyses of this substance showed peak of methyl 2,6,10-trimethyltridecanoate, the main component of male sexual pheromone. The sensory response to methyl 2,6,10-trimethyltridecanoate confirms that this compound may act as a kairomone to find host eggs. Females and egg mass stimuli were weakly attractive to the parasitoid.

Neotropical Entomology, 2008

In recent years the growing concern about environmental changes and how we are using the natural ... more In recent years the growing concern about environmental changes and how we are using the natural resources have triggered a search for natural products as alternatives to synthetic pesticides. The stink bugs produce a wide variety of chemical compounds (semiochemicals) that show potential to manage these insects. The stink bugs Chinavia impicticornis (Stål), C. ubica (Rolston), Dichelops melacanthus (Dallas), Euschistus heros (F.), Piezodorus guildinii (Westwood), Thyanta perditor (Westwood) and Tibraca limbativentris (Stål) had their blends of defensive compounds evaluated both qualitative and quantitatively. The main compounds identified on the glands of Brazilian stink bugs are: 2-alkenals, mainly the E isomer; saturated aliphatic hydrocarbons; and 4 oxo-(E)-2-alkenals. The first sex attractant determined from a stink bug was obtained from Nezara viridula L., and consists on a mix of two isomers cis - and trans bisabolene-epoxides. Later the soybean stink bug E. heros was also studied and its sex attractant was identified as three esters methyl: 2,6,10-trimethyldecanoate, methyl 2,6,10-trimethyldodecanoate, and methyl E2, Z4-decadienoate. Recently, three new Brazilian sting bugs were studied and had their sex attractant elucidated. Males of T. perditor produce the ester, methyl 2E,4Z,6Z-decatrienoate. Whereas, the stink bug, P. guildinii has as sexual pheromone, the sesquiterpene β-sesquiphellandrene, and the stink bug T. limbativentris produces as sex attractant the zingiberenol. In this review we discuss the advances obtained on the behaviour and identification of sex and defensive compound of stink bugs from Brazilian crops and the application of this knowledge to manage the stink bugs.

Journal of Chemical Ecology, 2011

Several studies have shown that herbivore-induced plant volatiles act directly on herbivores and ... more Several studies have shown that herbivore-induced plant volatiles act directly on herbivores and indirectly on their natural enemies. However, little is known about the effect of herbivore damage on resistant and susceptible plant cultivars and its effect on their natural enemies. Thus, the aim of this study was to evaluate the attraction of the herbivorous pentatomid bug Euschistus heros and its egg parasitoid Telenomus podisi to two resistant and one susceptible soybean cultivars with different types of damage (herbivory, herbivory+oviposition, and oviposition). In a Y-tube olfactometer, the parasitoids were attracted to herbivory and herbivory+oviposition damaged soybean plants when compared to undamaged soybean plants for the resistant cultivars, but did not show preference for the susceptible cultivar Silvânia in any of the damage treatments. The plant volatiles emitted by oviposition-damaged plants in the three cultivars did not attract the egg parasitoid. In four-arm-olfactometer bioassays, E. heros females did not show preference for odors of damaged or undamaged soybean plants of the three cultivars studied. The Principal Response Curves (PRC) analysis showed consistent variability over time in the chemical profile of volatiles between treatments for the resistant cultivar Dowling. The compounds that most contributed to the divergence between damaged soybean plants compared to undamaged plants were (E,E)-α-farnesene, methyl salicylate, (Z)-3-hexenyl acetate, and (E)-2-octen-1-ol.

Journal of Plant Interactions, 2008

Abstract Egg parasitoids have a short time frame in which their host eggs are suitable for parasi... more Abstract Egg parasitoids have a short time frame in which their host eggs are suitable for parasitism, and in several systems these parasitoids respond to plant volatiles induced by oviposition on the plant (either in isolation or in combination with feeding damage) as a ...

Pesquisa Florestal Brasileira, 2010

Resumo -A madeira de mogno, Swietenia macrophylla King, é valorizada no mercado internacional por... more Resumo -A madeira de mogno, Swietenia macrophylla King, é valorizada no mercado internacional por sua beleza e durabilidade para fins nobres, como mobiliários e decoração. Quaisquer tentativas de plantios comerciais dessa espécie de modo a reduzir a pressão exercida pela sua exploração seletiva invariavelmente fracassam devido à incidência da broca do ponteiro do mogno, Hypsipyla grandella (Zeller). Embora alguns trabalhos tenham obtido relativo sucesso em apresentar técnicas de controle sob aspectos pontuais, ainda não foi estabelecida uma estratégia de manejo integrado que seja prática, econômica e eficiente para H. grandella no Brasil. Este trabalho tem como objetivo rever e atualizar informações sobre o inseto e seu hospedeiro, além de indicar as áreas de pesquisa mais promissoras para o seu controle em plantios de S. macrophylla no País. As estratégias de controle de H. grandella mais recomendadas são o uso da resistência da planta, manejo silvicultural, uso de semioquímicos e controle biológico, nas quais há necessidade de incentivos a pesquisas de longo prazo. Ensaios de resistência natural de procedências de S. macrophylla devem ser incentivados, devido às extensas áreas com reservas naturais no Brasil.

Journal of Chemical Ecology, 2005

Olfactometer bioassays showed that odors from mature Thyanta perditor males attracted females but... more Olfactometer bioassays showed that odors from mature Thyanta perditor males attracted females but not males. Furthermore, odors from females did not attract either sex, indicating that like other phytophagous pentatomid bugs, the males produce a sex pheromone. Attraction appeared to peak in late afternoon to evening. The headspace volatiles collected from male and female T. perditor were analyzed by GC-MS and HPLC. A male-specific compound, methyl (2E,4Z,6Z)-decatrienoate (2E,4Z,6Z-10:COOMe), was identified along with a number of other compounds found in extracts from both sexes. Bioassays carried out with 2E,4Z,6Z-10:COOMe showed it was as attractive to females as the crude extract of male volatiles, suggesting that the male-produced sex pheromone consists of 2E,4Z,6Z-10:COOMe as a single component. Consecutive volatiles collections from males showed that 2E,4Z,6Z-10:COOMe began appearing in extracts from males about 9 d after the final molt, as the males became sexually mature.

Journal of Chemical Ecology, 2006

The male-produced sex pheromone from the Brazilian rice stalk stink bug Tibraca limbativentris is... more The male-produced sex pheromone from the Brazilian rice stalk stink bug Tibraca limbativentris is reported. Olfactometer bioassays with sexually mature males and females showed that males attracted females, which suggests that males release a sex pheromone. Males were not attracted to either sex, nor were females attractive to conspecific females. Attraction of the females to males was highest at night. The headspace volatiles collected from male and female bugs were analyzed by gas chromatography (GC) and GC–mass spectrometry. Two male-specific compounds were identified as isomers of 1′S-zingiberenol, whereas a series of defensive compounds were identified in extracts from both sexes. Zingiberenol has three chiral centers, and the nonselective syntheses used produced two groups of isomers, zingiberenol I containing four isomers, namely (1RS,4RS,1′R)-4-(1′,5′-dimethylhex-4′-enyl)-1-methylcyclohex-2-en-1-ol, and zingiberenol II containing the other four isomers, namely (1RS,4RS,1′S)-4-(1′,5′-dimethylhex-4′-enyl)-1-methylcyclohex-2-en-1-ol. Both groups of stereoisomers were more attractive than hexane controls. The absolute configuration of the insect-produced pheromonal components remains to be elucidated, but the 1′S stereochemistry was established for at least one of the isomers.

Animal Behaviour, 2007

Males and females of the Neotropical brown stink bug, Euschistus heros, communicate with vibrator... more Males and females of the Neotropical brown stink bug, Euschistus heros, communicate with vibratory songs transmitted through plants. In this study, we examined the responses of the egg parasitoid Telenomus podisi to vibratory signals of these bugs. Telenomus podisi females responded with orientated movements to the vibratory signals of female songs on plants and on an artificial substrate, whereas male songs, duets or continuous pure tone vibratory signals failed to elicit any response. In addition, T. podisi females had a higher turning rate when stimulated with female songs, indicating some effect on their kinetic behaviour. This is the first demonstration of a parasitoid eavesdropping on the sexual vibratory signals of insects. The potential mechanism of this directionality and its adaptive significance are discussed.

Journal of Chemical Ecology, 2009

We tested the hypotheses that host-searching behavior of the egg parasitoids Telenomus podisi and... more We tested the hypotheses that host-searching behavior of the egg parasitoids Telenomus podisi and Trissolcus basalis may be differentially influenced by the different blends of volatiles released from the metathoracic glands of adult stink bug host species. We further studied whether such a differential response is due to different individual components of these glands and whether these responses reflect host preferences. Y-tube olfactometer bioassays were carried out with crude extracts of metathoracic glands of five different host species of neotropical stink bugs. Additionally, we tested the parasitoids’ responses to synthetic standards of individual compounds identified in these stink bug glands. Results showed that females of T. basalis and T. podisi responded differentially to crude gland extracts of the different species of host stink bugs and to the compounds tested. The parasitoid T. basalis showed a positive taxic behavior to Nezara viridula methathoracxic gland extracts of a host species preferred in the field, i.e., N. viridula. Furthermore, T. basalis responded positively to 4-oxo-(E)-2-hexenal and (E)-2-decenal, two components of N. viridula glandular secretion. Higher residence time, reduced linear velocity, and higher tortuosity in the arm of the olfactometer supplied with 4-oxo-(E)-2-hexenal showed that this compound modifies the kinetics of some traits of T. basalis walking pattern and suggests that it might stimulate the searching behavior of this parasitoid. The parasitoid T. podisi was attracted to crude gland extracts of the preferred host (Euschistus heros) and also to 4-oxo-(E)-2-hexenal. Additionally, this parasitoid responded positively to (E)-2-hexenal and to the hydrocarbon tridecane, both of which are defensive compounds released from the metathoracic glands by several stink bugs. The results indicate some degree of specialization in the response of two generalist parasitoid species toward defensive secretions of stink bugs.

Parasitoids use herbivore-induced plant volatiles (HIPVs) to locate their hosts. However, there a... more Parasitoids use herbivore-induced plant volatiles (HIPVs) to locate their hosts. However, there are few studies in soybean showing the mechanisms involved in the attraction of natural enemies to their hosts and prey. The objective of this study was to evaluate the influence of volatile organic compounds (VOCs) of soybean, Glycine max (L.) Merr. (Fabaceae) (cv. Dowling), that were induced after injury caused by Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), on the searching behavior of the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Scelionidae). Four HIPVs from soybean, (E,E)-a-farnesene, methyl salicylate, (Z)-3-hexenyl acetate, and (E)-2-octen-1-ol, were selected, prepared from standards at various concentrations (10 À6 to 10 À1 M), and tested individually and in combinations using a two-choice olfactometer (type Y). Telenomus podisi displayed a preference only for (E,E)-a-farnesene at 10 À5 M when tested individually and compared to hexane, but they did not respond to the other compounds tested individually at any concentration or when combinations of these compounds were tested. However, the parasitoids stayed longer in the olfactometer arm with the mixture of (E,E)-a-farnesene + methyl salicylate at 10 À5 M than in the arm containing hexane. The results suggest that (E,E)-a-farnesene and methyl salicylate might help T. podisi to determine the presence of stink bugs on a plant. In addition, bioassays were conducted to compare (E,E)a-farnesene vs. the volatiles emitted by undamaged and E. heros-damaged plants, to evaluate whether (E,E)-a-farnesene was the main cue used by T. podisi or whether other minor compounds from the plants and/or the background might also be used to locate its host. The results suggest that minor volatile compounds from soybean plants or from its surroundings are involved in the host-searching behavior of T. podisi.

The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with a... more The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by cotton plants enhanced the attractiveness of the aggregation pheromone emitted by male boll weevils. Behavioral responses of A.